This invention relates to a press for full length resizing cartridge cases, removing primers, reseating new bullets in the neck ends and inserting a new primer in the socket at the head end of a case.
Typically, cartridge case reloading presses comprise a frame and a vertically reciprocable ram slideable in the frame toward and away from one or more dies into which a case is pressed by the ram for the purpose of performing such reloading operations as expelling the spent primer, resizing the case and pressing and crimping a new bullet in the case. In several types of reloading presses, the ram is driven by means of linkages comprising a compound lever system which is actuated by an arm that is swung by the user. Commonly, in prior art presses, an objective is to have the compound lever links toggle into a top dead center condition as the case is being pressed into the die so the highest possible force is applied to the case. Of all the reloading steps, the greatest amount of force is usually needed for the case resizing operation. A force on the ram of 100-1,500 pounds has been found to be sufficient to resize the largest cases used in ammunition available to civilians. Nevertheless, the makers of some presses now on the market claim that their frame and links are designed to withstand as much as 80,000 pounds of force which is far in excess of the force required for any of the case reloading operations. It has been observed that the reason for press manufacturers making each new model stronger than the last is that they are trying to prevent fractures or failure of the press parts resulting from misuse of the press. The most commonly occurring misuse is screwing in or adjusting a die relative to the ram such that the linkages driving the ram are toggling into their dead center condition as the case on the ram reaches the limit of its travel in the die. As the linkages of the compound lever system pass dead center, mechanical advantages approach infinity and a force is developed which can damage any press regardless of how strongly it is built. In reality it is only the spring or small elastic yield in the press frame and linkages that saves the press from destroying itself in most designs although damage occurs all too frequently in some brands of presses. As manufacturers attempt to strengthen some parts of the press, other parts ultimately take more of the load and yield to the overstress. Some presses now on the market claim a mechanical advantage of 189:1 just before toggling into dead center. Assuming that a user had adjusted a die too deeply and pushed the operating lever with a force of 75 pounds, the ram force could be on the order of 14,000 pounds or 10 times more than would ordinarily be necessary to size the largest cases commonly used by civilians. Thus, the prior art presses must be strong enough to withstand nearly 7 tons of force with no real benefit except to allow a user to use it improperly without having it fail. Except for the new reloading press disclosed herein, press manufacturers address the problem by making the parts of each new generation of presses of tougher and heavier steel forgings and castings. As a result, presses are becoming heavier, larger and more expensive.